In the UK alone, 500 000 people are infected with Hepatitis C virus (HCV) and still, most of the patients are not diagnosed. Therefore, HCV infection is a major cause of liver transplantation there. A few years ago, scientists have found monoclonal antibodies which gave hope for the acquisition of an effective vaccine. Now, the first results of the testing of vaccines based on adenoviral vectors have occurred.

180 million people worldwide is infected with Hepatitis C virus. Infection leads to the development of liver cancer and is the main cause of transplantation of this organ in the United Kingdom and the United States. Viral hepatitis treatment is expensive and effective only in half of the patients. Among not treated patients or not responding to the treatment, liver cirrhosis may develop, causing the need for transplantation.

Thanks to the collaboration of research groups from Europe and the USA, scientist from Nottingham University several years ago, indentified antibodies preventing effectively the infection of different strains of HCV in laboratory models. “The clinical potential of this work cannot be overstated. Historically, successful vaccines against viruses have required the production of antibodies, and this is likely to be the case for Hepatitis C virus”, said Dr Alexander Tarr from the Virus Research Group at the Nottingham University. “Identifying regions of the virus that are able to induce broadly reactive neutralising antibodies is a significant milestone in the development of a HCV vaccine, which will have distinct healthcare benefits for hepatitis sufferers, and could also help us design vaccines for other chronic viral diseases such as HIV.” “We are also currently exploring the possibility of improving liver transplantation success rates by passively infusing people with these antibodies” added Dr Tarr. “We are also using the information gained by identifying and characterising the antibody responses to Hepatitis C virus to design new ways of making vaccine candidates. If the antibodies we have discovered can be reproduced by vaccination, control of the disease might be possible.”

With an initial wave of enthusiasm, due to the discovery of neutralizing antibodies, at the same time research on obtaining practical empowering to fight HCV infection was continued. Recently, the first results of the application of vaccine based on adenoviral vectors have occurred. It has provoked strong and persistent response from T-cells among 27 healthy people. The response was assessed as constant, because it held for 52 weeks after vaccination. Individuals, who were vaccinated have reported good tolerance of the agent, with small or medium adverse effects. There was no report on serious adverse effects. What’s more, the same vaccine was given simultaneously with ribavirin to patients with chronic HCV infection. The vaccinated patients were never previously treated because of this disease. Strong immunogenicity of the vaccine was observed also among them. Most importantly, administration of the vaccine wasn’t associated with significant local or general adverse effects. Thanks to the satisfactory outcome of the first vaccine test results, further experiments are planned. It is expected that the vaccine will play not only preventive role, but it will improve the effectiveness of the HCV infection treatment. What will be the next step?

Written by: Karolina Kłoda MD, PhD

Source:
1. http://www.sciencedaily.com/releases/2007/09/070903204959.htm
2. European Association for the Study of the Liver. First vaccine for viral hepatitis C could become a reality.
3. ScienceDaily. Retrieved January 22, 2012, from http://www.sciencedaily.com/releases/2011/04/110401121329.htm
4. http://medtube.pl/patomorfologia/filmy-medyczne/3279-histopatologia-watroby-aktywne-zapalenie-watroby-marskosc

Want to know more about liver? Watch on medtube.net “Histopathology of Liver – Chronic active hepatitis, cirrhosis”